TimHwrote a review of Castelli Superleggera Vest - Men's on October 30, 2019
Familiarity: I've used it several times
The Pertex Quantum face fabric on this vest isn't windproof as stated in the description. I can put my mouth against the front face fabric and blow air through it. Cold air gets through while I ride. It isn't coming through the zipper or around the arm holes either but directly through the fabric.
It simply does not block all the wind, or enough of it to be really useful. Fit is good with no flapping but why bother if it doesn't block the wind?
I also own a Castelli Pro Light Wind Vest (discontinued). It blocks 100% of the wind and has better ventilation in the rear. Buy one if you find it available in your size. I wanted another vest that wasn't flouro. The only reason why I bought the Superleggera is because they didn't have the Pro Light in the color/size I wanted. Performance of the Superleggera is nowhere near as good as the Pro Light.